The present invention relates generally to rechargeable battery cells and more particularly concerns a flat plastic case for such cells.
During recent years there has been a tremendous growth in the manufacture and use of minature electronic devices such as hand-held calculators. Most of these devices are designed to operate on self-contained batteries in addition to being operable when plugged into a conventional electrical outlet, with or without an adapter. Many of the battery operated models utilize rechargeable batteries which, if properly and periodically recharged, last for long periods of time before replacement is required. However, one of the limitations on the physical design of hand-held calculators and the like which use rechargeable batteries has been the size and shape of conventional rechargeable batteries, most of which are cylindrical in shape and relatively space consuming.
Accordingly it is the primary aim of the present invention to provide a thin, flat case for a rechargeable battery cell.
A more specific object is to form such a cell case out of plastic material which can be inexpensively molded in two parts and then bonded together after insertion of the electrode and separator material.
It is a more detailed object to provide a thin, flat plastic battery cell case of the above type with internal restraints which prevent bulging or other deformation of the case upon a build-up of internal pressure within the case.
These and other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings, in which: